Pressure sensitive adhesive(s) and articles(s)

ABSTRACT

A pressure sensitive adhesive tape that employs a water-dispersible polymer is provided. The adhesive can comprise microparticles and a water-dispersible component; or microparticles and a novel water-dispersible polymer that contains a plurality of poly(alkoxyalkyl)acrylate units as a major component. The tape may be used with labels for containers, sterilization indicator tapes and labels, surgical wrappers, mammalian body coverings, and in the preparation of paper web splices. The tape may be repulpable and/or laundearable.

This is a division of application Ser. No. 08/222,458 filed Apr. 4,1994, now U.S. Pat. No. 5,512,612.

FIELD OF THE INVENTION

This invention relates to pressure sensitive adhesives and articles madetherefrom.

BACKGROUND OF THE INVENTION

Pressure sensitive adhesives (PSAs) have gained wide spread acceptancein many applications. These adhesives are characterized by beingnormally tacky at room temperature (e.g., 20° C.) and forming a bond toa surface by the application of, at most, very light finger pressure.They possess a balance of viscoelastic and elastic properties whichresult in a four-fold balance of adhesion, cohesion, stretchiness andelasticity. They have sufficient cohesiveness and elasticity so thatthey can be handled and removed from surfaces without leaving a residueeven though they are tacky. PSAs do not embrace compositions merelybecause they are sticky or adhere to a surface.

Microparticle-containing PSAs represent one category of PSAs. Thiscategory of PSAs contains a plurality of microparticles which may or maynot be inherently pressure sensitive and may or may not be hollow.Microparticle-containing PSAs may also include a binder to assist insecuring the particles to a substrate. The binder may be inherentlypressure sensitive if desired. Examples of these PSAs are disclosed inthe art. For example, see U.S. Pat. No. 3,857,731 (Merrill et al), U.S.Pat. No. 4,656,218 (Kinoshita), U.S. Pat. No. 4,735,837 (Miyasaka etal), U.S. Pat. No. 4,855,170 (Darvall et al), U.S. Pat. No. 4,994,322(Delgado et al), U.S. Pat. No. 5,118,750 (Silver et al), and WO 93/02855(Mallya et al). The adhesives disclosed in these references are notwater-dispersible. They agglomerate and form tacky globules whenattempts are made to repulp them. The globules, commonly referred to as"stickles" in the art, plug screens used in the repulping process andlead to increased manufacturing time and expense. Additionally, anyglobules that are not removed by screening adversely affect the qualityof the paper product resulting from such recycling efforts. As a resulta need exists for a water-dispersible pressure sensitive microparticleadhesive that can be readily repulped.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages of the prior art. Inone aspect of the invention it provides a normally tacky pressuresensitive adhesive composition made up of a blend of:

A) a polymeric, solvent insoluble but solvent dispersible microparticlecomponent; and

B) a water-dispersible polymeric component.

The microparticle component comprises from 0.1 to 99.9 parts by weightof the adhesive composition, more preferably, from 10 to 95 parts byweight. The water-dispersible component correspondingly comprises from99.9 to 0.1 parts by weight of the adhesive composition, morepreferably, from 90 to 5 parts by weight. The microparticle componentmay be tack free.

In another aspect of the invention there is provided a water-dispersiblepressure sensitive adhesive composition that comprises the product ofthe emulsion polymerization product of

A) from about 50 to 98 parts by weight, preferably from about 80 to 95parts by weight, of a poly(alkoxyalkyl) acrylate; and correspondingly

B) from about 50 to 2 parts by weight, preferably from about 20 to 5parts by weight, of a carboxylic acid. These polymers, which containprimarily poly(alkoxyalkyl) acrylate units are pressure sensitive in andof themselves.

In another embodiment of the invention, the normally tacky pressuresensitive adhesive comprises:

(A) from 10 to 95 parts by weight of a microparticle component whichcomprises the emulsion polymer of

(1) 100 parts by weight or less of at least one free radicallypolymerizable monomer selected from the group consisting of alkylacrylate esters, alkyl methacrylate esters, vinyl esters and mixturesthereof;

(2) 0 to 30 parts by weight of at least one polar monomercopolymerizable with the free radically polymerizable monomer of partA(1); and

(3) 0 to 40 parts by weight of at least one hydrophilic oligomer orpolymer copolymerizable with either of the free radically polymerizablemonomer A(1) and the polar monomer A(2), and correspondingly from 90 to5 parts by weight of a

(B) water-dispersible polymer component which comprises the polymer of:

(1) 50 to 98 parts by weight of a poly(alkoxyalkyl) acrylate; andcorrespondingly

(2) 50 to 2 parts by weight of a carboxylic acid.

The adhesive composition of the invention is preferablywater-dispersible. It has improved performance in one or more of tack,adhesion, and humidity resistance when compared to the compositions ofthe prior art. It may be provided either in bulk form or as a PSA sheetof any desired width, that is as a narrow strip or a tape or as a widefilm. In either case, the pressure sensitive sheet comprises a thinlayer (typically less than 125 μ thick. Additionally, the adhesive layermay be provided on one or more opposed (e.g., first and second) surfacesof a flexible support. If the adhesive layer is strippably bonded to thesupport, the resulting product is an adhesive transfer tape. If theadhesive is essentially permanently bonded to the support, the supportis referred to herein as a backing. The adhesive layer may be providedon at least a portion of a first side of the flexible support, and alayer of a release agent may be provided on at least a portion of asecond side of the flexible support. Such products may further includeindicia thereon.

The adhesive film of the present invention is useful in a variety ofapplications. For example, it can be used in the manufacture ofrepulpable paper splices (both permanent and temporary) which may jointogether first and second repulpable sheets. Additionally, suchadhesives can be used with labels for containers, sterilizationindicator tapes and labels, fabric, closure systems for containers suchas envelopes, closure systems for surgical wrappers, and mammalian bodycoverings (e.g., surgical gowns, sheets, drapes and the like). Otheruses for the adhesive and tape of the invention will be apparent tothose skilled in the art as a result of this disclosure.

As used throughout this specification, the following terms have thefollowing meanings:

"Water-dispersible" means that the particular material is capable ofpassing either the TAPPI test UM-213 or the Laundering Test each ofwhich is described in more detail below.

"Blend" means to a physical combination of the microparticles and thewater-dispersible polymeric component. The components are not covalentlybonded to one another although they may be associated via hydrogenbonding.

DETAILED DESCRIPTION

The Microparticle Component

The microparticle component useful in the invention is comprised ofpolymeric, elastomeric, solvent insoluble but solvent dispersiblemicroparticles. These spheres may be inherently pressure sensitive ifdesired, although they need not be so. Additionally, a crosslinker maybe added if desired. As manufactured, the microparticles are generallyspheroidal in shape. They typically have an average diameter in therange of from 1 to 300 (preferably from 1 to 50) μ. The microparticlesused in the invention may be solid or hollow. Hollow microparticles maycontain more than one void. Typically, the hollow or void portion of themicroparticles is less than 100 μm in average diameter.

The microparticles may be prepared by various emulsification processes.For example the microparticles may be obtained via suspensionpolymerization such as the following "two-step" emulsificationpolymerization process comprising the steps of:

a) forming

(i) forming a water-in-oil emulsion by mixing an aqueous solution ofpolar monomer(s) with oil phase monomer(s), the oil phase monomer(s)being selected from alkyl (meth)acrylate esters and vinyl esters; and

(ii) forming a water-in-oil-in-water emulsion by dispersing thewater-in-oil emulsion into an aqueous phase; and

b) initiating polymerization, preferably by application of heat orradiation.

In this process, the first step preferably involves forming awater-in-oil emulsion of an aqueous solution of monomer(s) (at leastsome of which is a polar monomer) in an oil phase monomer, i.e., atleast one (meth)acrylate or vinyl ester monomer, with optional freeradically reactive hydrophilic oligomers and/or polymers, using anemulsifier having a low hydrophilic-lipophilic balance (HLB) value.Suitable emulsifiers are those having an HLB value below about 7,preferably in the range of about 2 to about 7. Examples of suchemulsifiers include sorbitan monooleate, sorbitan trioleate, andethoxylated oleyl alcohol such as Brij™ 93, available from AtlasChemical Industries, Inc.

In the first phase of the first step, oil phase monomer(s), emulsifier,a free radical initiator, and, optionally, free radically reactivehydrophilic oligomer and/or polymer, and, optionally, a crosslinkingmonomer or monomers as defined below are combined, and an aqueoussolution of all or a portion of the polar monomer(s) is agitated andpoured into the oil phase mixture to form a water-in-oil emulsion. Thefree radically reactive hydrophilic oligomer and/or polymer, may beadded to either the oil phase or the water phase. A thickening agent,e.g., methyl cellulose may also be included in the aqueous phase of thewater-in-oil emulsion. In the second phase of the first step, awater-in-oil-in-water emulsion is formed by dispersing the water-in-oilemulsion of the first step into an aqueous phase containing anemulsifier having an HLB value above about 6. The aqueous phase may alsocontain any portion of the polar monomer(s) which was not added in stepone. Examples of such emulsifiers include ethoxylated sorbitanmonooleate; ethoxylated lauryl alcohol; and alkyl sulfates. In bothsteps, when an emulsifier is utilized, its concentration should begreater than its critical micelle concentration,which is herein definedas the minimum concentration of emulsifier necessary for the formationof micelles, i.e., submicroscopic aggregations of emulsifier molecules.Critical micelle concentration is slightly different for eachemulsifier, usable concentrations ranging from about 1.0×10⁻⁴ to about3.0 moles/liter. Additional detail concerning the preparation ofwater-in-oil-in-water emulsions, i.e., multiple emulsions, may be foundin various literature references, e.g., Surfactant Systems: TheirChemistry, Pharmacy, & Biology, (D. Attwood and A. T. Florence, Chapman& Hall Limited, New York, 1983). If the water-in-oil-in-water emulsionis stable, then hollow or multi-void microparticles will be formed.

The second, or final process step of this method involves theapplication of heat or radiation to initiate polymerization of themonomers. Useful initiators are those which are normally suitable forfree radical polymerization of acrylate or vinyl ester monomers andwhich are oil soluble and of very low solubility in water. However, whenthe polar monomer is N-vinyl pyrrolidone, the use of benzoyl peroxide asthe initiator is recommended. Examples of such initiators include azocompounds, hydroperoxides, peroxides, and the like, and photoinitiatorssuch as benzophenone, benzoin ethyl ether, and 2,2-dimethoxy-2-phenylacetophenone.

Use of a water soluble polymerization initiator causes formation ofsubstantial amounts of latex. The extremely small particle size of latexparticles renders any significant formation of latex undesirable. Theinitiator is generally used in an amount ranging from about 0.01 percentup to about 10 percent by weight of the total polymerizable composition,preferably up to about 5 percent.

Microparticles may also be prepared by a simpler ("one-step")emulsification process comprising aqueous suspension polymerization ofat least one alkyl (meth)acrylate ester monomer or vinyl ester monomerand, optionally, at least one polar monomer in the presence of at leastone emulsifier which is capable of producing a water-in-oil emulsioninside the droplets, which is substantially stable during emulsificationand polymerization. In this process the aqueous suspension optionally,and preferably, also includes a free radically reactive hydrophilicoligomer and/or polymer.

As in the two-step emulsification process, the emulsifier is utilized inconcentrations greater than its critical micelle concentration. Examplesof such emulsifiers include alkylaryl ether sulfates such as sodiumalkylaryl ether sulfate, e.g., Triton™ W/30, available from Rohm andHaas; alkylaryl poly(ether) sulfates such as alkylaryl poly(ethyleneoxide) sulfates, preferably those having up to about 4 ethoxy repeatunits; and alkyl sulfates, such as sodium lauryl sulfate, ammoniumlauryl sulfate, triethanolamine lauryl sulfate, and sodium hexadecylsulfate; alkyl ether sulfates such as ammonium lauryl ether sulfate; andalkyl poly(ether) sulfates, such as alkyl poly(ethylene oxide) sulfates,preferably those having up to about 4 ethoxy units. Alkyl sulfates;alkyl ether sulfates; alkylaryl ether sulfates; and mixtures thereof arepreferred as they provide a maximum void volume per microparticle for aminimum amount of surfactant. Nonionic emulsifiers, e.g., Siponic™Y-500-70 (ethoxylated oleyl alcohol, available from Alcolac, Inc.); andPLURONIC® P103 (a block copolymer of poly(propylene oxide) andpoly(ethylene oxide), available from BASF Corporation) can be utilizedalone or in conjunction with anionic emulsifiers. Polymeric stabilizersmay also be present but are not necessary.

Both the "two-step" and "one-step" methods produce an aqueous suspensionof monomer droplets. Upon polymerization the droplets becomemicroparticles. The majority of the microparticles have interiorcavities that, upon drying, become voids.

Another process which may be used to prepare the microparticles forms anoil-in-water emulsion and then disperses the emulsion into an aqueousphase. The aqueous phase comprises at least one alkyl (meth)acrylateester monomer or vinyl ester monomer, and optionally a free radicallyreactive hydrophilic oligomer and/or polymer. This process employs asuspension stabilizer rather than an emulsifier. As a result, thisprocess forms monomer droplets which have no interior cavities. Uponpolymerization, these droplets become solid microparticles.

Discrete polymeric microparticles may also be prepared via suspensionpolymerizations as disclosed in U.S. Pat. Nos. 3,691,140; 4,166,152;4,636,432; 4,656,218; and 5,045,569 which all describe adhesivecompositions.

Preparation of the microparticles of this invention may be modified bywithholding the addition of all or part of the optional free radicallyreactive hydrophilic oligomer and/or polymer, and optionally polarmonomers until after polymerization of the oil phase is initiated;however, the components must be added to the polymerizing mixture priorto 100% conversion.

The microparticles may be prepared from a number of materials. Forexample, alkyl acrylate and methacrylate monomers may be used to preparethe spheres. These monomers are monofunctional unsaturated acrylate andmethacrylate esters of non-tertiary alkyl alcohols. The alkyl groups ofthese alcohols preferably contain from 4 to 14 carbon atoms. Theseacrylate monomers are oleophilic, water emulsifiable, have restrictedwater solubility, and as homopolymers, generally have glass transitiontemperatures below about -10° C. Examples of such monomers include butare not limited to those selected from the group consisting of isooctylacrylate, 4-methyl-2-pentyl acrylate, 2-methylbutyl acrylate, isoamylacrylate, sec-butyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate,isodecyl methacrylate, isononyl acrylate, isodecyl acrylate, andmixtures thereof.

Preferred acrylate monomers include those selected from the groupconsisting of isooctyl acrylate, isononyl acrylate, isoamyl acrylate,isodecyl acrylate, 2-ethylhexyl acrylate, n-butyl acrylate, sec-butylacrylate, and mixtures thereof.

Acrylate or methacrylate or other vinyl monomers which, as homopolymers,have glass transition temperatures higher than about -10° to 0° C.,e.g., tert-butyl acrylate, isobornyl acrylate, butyl methacrylate, vinylacetate, acrylonitrile, mixtures thereof, and the like, may optionallybe utilized in conjunction with one or more of the acrylate,methacrylate and vinyl ester monomers provided that the glass transitiontemperature of the resultant polymer is below about -10° C.

Vinyl ester monomers suitable for use in the microparticles include butare not limited to those selected from the group consisting of vinyl2-ethylhexanoate, vinyl caprate, vinyl laurate, vinyl pelargonate, vinylhexanoate, vinyl propionate, vinyl decanoate, vinyl octanoate, and othermonofunctional unsaturated vinyl esters of linear or branched carboxylicacids comprising 1 to 14 carbon atoms which as homopolymers have glasstransition temperatures below about -10° C. Preferred vinyl estermonomers include those selected from the consisting of vinyl laurate,vinyl caprate, vinyl 2-ethylhexanoate, and mixtures thereof.

The polar monomers useful in preparing the microparticles are bothsomewhat oil soluble and water soluble, resulting in a distribution ofthe polar monomer between the aqueous and oil phases. Representativeexamples of suitable polar monomers include but are not limited to thoseselected from the group consisting of acrylic acid; methacrylic acid;itaconic acid; crotonic acid; maleic acid; fumaric acid; sulfoethylmethacrylate; and ionic monomers such as sodium methacrylate; ammoniumacrylate; sodium acrylate; trimethylamine p-vinyl benzimide;N,N-dimethyl-N-(beta-methoxy-ethyl)ammonium propionate betaine;trimethylamine methacrylamide; 1,1-dimethyl-1-(2,3-dihydroxypropyl)aminemethacrylamide; N-vinyl pyrrolidone; N-vinyl caprolactam; acrylamide;t-butyl acrylamide; dimethylamino ethyl acrylamide; N-octyl acrylamide;mixtures thereof, and the like. Preferred polar monomers include thoseselected from the group consisting of monoolefinic monocarboxylic acids;monoolefinic dicarboxylic acids; acrylamides; N-substituted acrylamides;salts thereof, and mixtures thereof. Examples of such monomers includebut are not limited to those selected from the group consisting ofacrylic acid; sodium acrylate; N-vinyl pyrrolidone; and mixturesthereof.

Optionally there may be included free radically reactive hydrophilicoligomers and/or polymers in the microparticles. These include but arenot limited to those selected from the group consisting of poly(alkyleneoxides) such as poly(ethylene oxide); poly(vinyl methyl ether);poly(acrylamide); poly-(N-vinyl pyrrolidone); poly(vinyl alcohol); andmixtures thereof.

Functionalized derivatives of free radically reactive hydrophilicoligomers and polymers useful in the microparticles include thoseselected from the group consisting of macromers of the general formula:

    X--(Y).sub.n --Z

wherein

X is a group that is free radically copolymerizable with the freeradically polymerizable monomer(s) and polar monomer(s);

Y is a divalent linking group;

n is an integer of 0 to 1;

Z is a monovalent hydrophilic polymeric or oligomeric moiety having adegree of polymerization greater than or equal to 2.

Examples of such macromonomers include but are not limited to thoseselected from the group consisting of acrylate and methacrylatefunctional oligomers and polymers, where X represents H₂ C═CR¹ --, whereR¹ represents H or CH₃ ; Y is a divalent carboxyl group; n=1; and Z is ahydrophilic oligomeric or polymeric moiety having a degree ofpolymerization greater than or equal to 2. Such macromonomers alsoinclude but are not limited to p-styryl functional materials, Xrepresents H₂ C═CR¹ --, where R¹ represents H or CH₃ ;

Y represents ##STR1## n=1; and Z is a hydrophilic oligomeric orpolymeric moiety having a degree of polymerization greater than or equalto 2. Difunctional or multifunctional oligomers and polymers having morethan one X group radically copolymerizable with the free radicallycopolymerizable monomers and polar monomers of the microparticles usedin the present invention, such X groups either pendant from orterminating hydrophilic polymeric or oligomeric moiety Z, are alsouseful in the microparticles of the present invention.

Preferred macromonomers include those selected from the group consistingof acrylate terminated poly(ethylene oxide); methacrylate terminatedpoly(ethylene oxide); methoxy poly(ethylene oxide) methacrylate; butoxypoly(ethylene oxide) methacrylate; p-vinyl benzyl terminatedpoly(ethylene oxide); acrylate terminated poly(ethylene glycol);methacrylate terminated poly(ethylene glycol); methoxy poly(ethyleneglycol) methacrylate; butoxy poly(ethylene glycol) methacrylate, p-vinylbenzyl terminated poly(ethylene glycol); poly(ethylene oxide)diacrylate; poly(ethylene oxide) dimethacrylate; and mixtures thereof.These functionalized materials are preferred because they are easilyprepared through well-known ionic polymerization techniques and are alsohighly effective in providing grafted hydrophilic segments along freeradically polymerized acrylate polymer backbones.

Preferred macromonomers also include those selected from the groupconsisting of p-vinyl benzyl terminated poly(N-vinyl pyrrolidone);p-vinyl benzyl terminated poly(acrylamide); methacrylate terminatedpoly(N-vinyl pyrrolidone); and mixtures thereof. These macromonomers maybe prepared through the esterification reaction of a carboxy terminatedN-vinyl pyrrolidone or acrylamide, beta-mercaptopropionic acid chaintransfer agent, and chloromethyl styrene or methacryloyl chloride asdescribed in a series of papers by M. Akashi et al. [Angew. Makromol.Chem., 132, 81 (1985); J. Appl. Polym. Sci., 39, 2027 (1990); J. Polym.Sci., Part A: Polym. Chem., 27, 3521 (1989] all incorporated byreference herein.

Preferably at least one polar monomer is included in the composition,but microparticles may also be prepared using alkyl acrylate, alkylmethacrylate and/or vinyl ester monomer(s) alone or in combination onlywith other vinyl free radically polymerizable monomers, e.g., vinylacetate. However, when a methacrylate monomer alone is utilized, acrosslinking agent, must be included unless the hydrophilic componentcomprises more than one radically copolymerizable group X as defined inFormula I. Most preferably at least about 1 part to about 10 parts byweight polar monomer is included as this ratio provides microparticleswith balanced PSA properties.

The composition from which the microparticles are made may also containa multifunctional crosslinking agent. The term "multifunctional" as usedherein refers to crosslinking agents which possess two or more freeradically polymerizable ethylenically unsaturated groups. Usefulmultifunctional crosslinking agents include those selected from thegroup consisting of acrylic or methacrylic esters of diols such asbutanediol diacrylate, triols such as glycerol, and tetrols such aspentaerythritol. Other useful crosslinking agents include those selectedfrom the group consisting of polymeric multifunctional acrylates andmethacrylates, e.g., poly(ethylene oxide) diacrylate or poly(ethyleneoxide) dimethacrylate; polyvinylic crosslinking agents, such assubstituted and unsubstituted divinylbenzene; and difunctional urethaneacrylates, such as Ebecryl™ 270 and Ebecryl 230™ (1500 weight averagemolecular weight and 5000 weight average molecular weight acrylatedurethanes, respectively--both available from Radcure Specialties), andmixtures thereof.

The microparticles useful in this invention are preferably comprised,based on 100 parts by weight total, of 100 parts or less of at least onefree radically polymerizable monomer selected from the group consistingof alkyl acrylate esters, alkyl methacrylate esters, vinyl esters, andmixtures thereof; and optionally about 0 to about 30 parts by weight ofone or more polar monomers; and optionally about 0 to about 40 parts byweight of at least one hydrophilic oligomer or polymer component.

Preferably the pressure sensitive microparticles comprise about 80 toabout 98 parts of free radically polymerizable monomer selected from thegroup consisting of alkyl acrylate esters, alkyl methacrylate esters,vinyl esters, and mixtures thereof; and optionally about 1 to 17 partsof at least one polar monomer; and optionally about 1 to 18 parts of ahydrophilic oligomer or polymer component, based on 100 parts by weighttotal. Most preferably the pressure sensitive microparticles compriseabout 87 to about 98 parts of free radically polymerizable monomer; andoptionally about 1 to 8 parts of a polar monomer; and optionally about 1to 5 parts of a hydrophilic oligomer or polymer component, based on 100parts by weight total.

When a crosslinker is employed, it is typically employed at a level ofup to about 10 equivalent weight percent. Above about 0.15 equivalentweight percent, of the total polymerizable microparticle composition,the microparticles become non-tacky. The "equivalent weight percent" ofa given compound is defined as the number of equivalents of thatcompound divided by the total number of equivalents in the total(microparticle) composition, wherein an equivalent is the number ofgrams divided by the equivalent weight. The equivalent weight is definedas the molecular weight divided by the number of polymerizable groups inthe monomer (in the case of those monomers with only one polymerizablegroup, equivalent weight=molecular weight). The crosslinker can be addedat any time before 100% conversion to polymer of the monomers of saidmicroparticle composition. Preferably it is added before initiationoccurs.

The relative amounts of the above components are important to theproperties of the resultant microparticle. Use of higher levels of amultifunctional crosslinker will result in nontacky microparticles. Insuch cases the water soluble, or dispersible, polymeric component mustbe tacky. In those cases where the water soluble, or dispersible,polymeric component is not itself tacky, it is necessary for themicroparticle adhesive to be so.

The Water-Dispersible Polymeric Component

The polymeric component useful in the invention comprises sufficienthydrophilic units capable of rendering the polymer water-dispersible.Preferably, the polymeric component contains functional groups which arecapable of interacting with the microspheres. Such functional groupsinclude, by way of example, hydroxyl groups, carboxyl groups, aminogroups, sulfonyl groups, and the like. Adhesives of the invention whichemploy polymeric components with these types of functional groups havebeen found to exhibit improved shear strength.

A wide variety of water-dispersible materials are useful as thepolymeric component in the invention. Non-limiting examples of thesematerials include those selected from the group consisting ofsurfactants such as poly(ethylene oxide) alkylphenyl ethers, such asthose sold under the name IGEPAL® CO and IGEPAL® CA (available fromRhone-Poulenc, Inc.); poly(ethylene oxide) lauryl, cetyl, and oleylethers such as those sold under the name Brij® (available from ICIAmericas, Inc.); poly(ethylene oxide) laurate; poly(ethylene oxide)oleate; sorbitan oleate; ethylene oxide/propylene oxide block copolymerssuch as those sold under the name PLURONIC® and TETRONIC® (availablefrom BASF Corporation); and organic phosphate esters, such as Gafac®PE-510 (available from International Specialty Products).

Other water-dispersible polymers useful in the invention include thosedisclosed in U.S. Pat. Nos. 2,838,421, 3,441,430, 4,442,258, 3,890,292,and 5,196,504, and DE-C 23 11 76. Examples of such components includebut are not limited to those selected from the group consisting ofpoly(acrylic acid); poly(vinyl alcohol); poly(N-vinyl pyrrolidone);poly(acrylamide); poly(alkoxyalkyl (meth)acrylates), such as 2-ethoxyethyl acrylate, 2-ethoxy ethyl methacrylate, 2-(2-ethoxyethoxy) ethylacrylate, and 2-methoxy ethyl acrylate (available from SARTOMER Company,Inc.); poly(vinyl methyl ether); poly(vinyl methyl ether: maleicanhydride), sold under the name Gantrez™ (available from InternationalSpecialty Products); poly(ether polyols), such as poly(propylene glycol)and the like, such as those sold under the name Sannix™ (available fromSanyo Chemical Industries); copolymers thereof, and the like. Copolymersof these and alkyl (meth)acrylate esters or vinyl esters are alsosuitable. Gums such as those derived from okra and guar may also beused.

A particularly useful water-dispersible polymer comprises the pressuresensitive emulsion polymers disclosed above. When the emulsion polymeris combined with the microparticles a pressure sensitive adhesivecomposition is produced which has optimal shear strength. These emulsionpolymers comprise the polymerization product of a poly(alkoxyalkyl)acrylate, and a carboxylic acid. Additionally, an essentiallywater-insoluble alkyl acrylate and a copolymerizable emulsifier monomermay be included in the polymerization components. The alkyl acrylatetypically comprises from 0 to 40 parts by weight, preferably 0 parts byweight, of the polymerization mixture. The emulsifier monomer typicallycomprises from 0 to 6 parts by weight, preferably 0 to 4 parts byweight, of the polymerization mixture.

Examples of poly(alkoxyalkyl) acrylates useful in preparing the emulsionpolymer include but are not limited to those selected from2-(2-ethoxyethoxy) ethyl acrylate, 2-ethoxyethyl acrylate,2-methoxyethoxyethyl acrylate, 2-methoxyethyl methacrylate, polyethyleneglycol monoacrylates and methacrylates, and the like.

Examples of carboxylic acids useful in preparing the emulsion polymerinclude but are not limited to those selected from acrylic acid,methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaricacid, beta-carboxyethyl acrylate, and the like.

Examples of alkyl acrylates useful in preparing the emulsion polymerinclude but are not limited to those selected from methyl(meth)acrylate, ethyl(meth) acrylate, n-butyl(meth) acrylate, 2-methylbutylacrylate, isoamyl acrylate, sec-butyl acrylate, isooctyl acrylate,2-ethylhexyl acrylate, isononyl acrylate, isodecyl acrylate, and thelike.

Examples of copolymerizable surfactant monomers useful in preparing theemulsion polymer include but are not limited to those which are anionicvinyl functional surfactants, such as sodium vinyl sulfonate, sodiumstyrene sulfonate, alkylene polyalkoxy sulfates, and the like.

Another polymeric component useful in the microparticle-containingadhesive of the invention is described in copending application Ser. No.08/093,080. This application discloses a pressure sensitive adhesivepolymer comprised of AA, BB and CC monomers. The AA monomer is ahydrophobic monomer selected from the group consisting of an acrylic ora methacrylic ester of a non-tertiary alcohol having from 2 to 14 carbonatoms. The AA monomer comprises from 50 to 80% by weight of AA plus BBplus CC monomers. The BB monomer is selected from β-carboxyethylacrylate (BCEA) or a salt thereof, and mixtures of BCEA or a saltthereof, and other vinyl carboxylic acids or a salt thereof. The BBmonomer comprises from about 10 to about 30% by weight of AA plus BBplus CC monomers. If a mixture of BCEA and the vinyl carboxylic acid orits salt is used, the BCEA must comprise at least 10% by weight of thepolymer. Additionally, the carboxylic acid groups of the polymer havebeen neutralized with an alkali metal hydroxide. The quantity of thehydroxide used to neutralize the acid groups is from about 0.5 to 2equivalents of the hydroxide per acid group. The CC monomer is awater-dispersible macromolecular monomer which has the formula X-Y-Z. Inthe C monomer, X is a moiety copolymerizable with AA and BB, Y is adivalent linking group which joins X to Z and Z is a water-dispersiblegroup which contains at least two units which are essentially unreactiveunder free radical initiated copolymerization conditions which can beused to form the polymer. CC comprises from 10 to 30% by weight of theAA plus BB plus CC monomers.

This pressure sensitive polymer typically has an inherent viscosity (IV)at 27.5° C. in 1-butanone of from 0.2 to over 2 dl/g. Preferably the IVis in the range of 0.7 to 1.5 dl/g. Most preferably the IV is in therange of from 0.9 to 1.4 dl/g.

The AA monomer useful in preparing the terpolymer is a hydrophobicmonomeric acrylic or methacrylic ester of a non-tertiary alcohol, whichalcohol contains from 2 to 14 carbon atoms and preferably from 4 to 12carbon atoms. It is preferred that the non-tertiary alcohol be an alkylalcohol. The term "hydrophobic" is used herein to mean that the AAmonomer lacks substantial affinity for water, that is, it neithersubstantially adsorbs nor absorbs water at room temperature.

Examples of monomers suitable for use as the A monomer include theesters of either acrylic acid or methacrylic acid with non-tertiaryalcohols such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol,1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 1-hexanol,2-hexanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2-ethyl-1-butanol,3,5,5-trimethyl-1-hexanol, 3-heptanol, 1-octanol, 2-octanol,isooctylalcohol, 2-ethyl-1-hexanol, 1-decanol, 1-dodecanol,1-tridecanol, 1-tetradecanol and the like. The preferred AA monomer isthe ester of acrylic acid with butyl alcohol or isooctyl alcohol or acombination thereof, although combinations of two or more different AAmonomers are suitable.

Monomer AA is preferably present in an amount of 50 to 80% by weightbased on the total monomer content used to prepare the terpolymer. Morepreferably monomer AA is present in an amount of 60 to 75% by Weight.

The BB monomer useful in preparing the terpolymer is polar and iscopolymerizable with the AA and CC monomers. It is either BCEA or a saltthereof, or a mixture of BCEA or a salt thereof and vinyl carboxylicacid such as acrylic acid or a salt thereof. Examples of useful vinylcarboxylic acids include acrylic acid, methacrylic acid, itaconic acid,maleic acid and fumaric acid. BCEA is a commercially available material.It is provided as a mixture of ingredients. For example, BCEA isavailable from Rhone Poulenc, Cranbury, N.J. as a mixture of 20 weight %acrylic acid, 40 weight % BCEA and 40 weight % other acrylic acidoligomers. Preferably, the amount of BB monomer mixture used to preparethe polymer is in the range of 10-20 weight %.

A neutralizing agent is employed in the manufacture of this polymer. Itis employed at a level sufficient to neutralize at least 50% of theadhesive copolymer acid moiety. Excess neutralizing agent, i.e., up to 2equivalents of neutralizing per acid group may be employed. Preferablyfrom 0.75 to 1.5 equivalents of neutralizing agent per acid group areemployed. Neutralization is achieved via the use of an alkali metalhydroxide or a combination of an alkali metal hydroxide with a minoramount of another neutralizing agent. A wide variety of otherneutralizing agents may be used as will be understood by those skilledin the art. The selection of the other neutralizing agent, and theamount employed may be varied to achieve a desired result. However, thetype and amount selected must not render the adhesive non-dispersible.Preferably sodium and potassium hydroxide are used as neutralizingagents.

The CC monomer useful in preparing the terpolymer is a water-dispersiblemacromolecular monomer. Preferably the CC monomer contains only onevinyl group copolymerizable with the AA and BB monomers.

Typically, the CC monomer contains a plurality of hydrophilic siteswhich impart the required hydrophilicity of the monomer.

A preferred X group of the CC monomer is a vinyl group of the generalformula II

    H.sub.2 C═CR.sup.1 --

wherein R¹ is a hydrogen atom or a methyl group.

A preferred Y group of the CC monomer is a divalent carbonyl group.

A preferred Z moiety of the CC monomer is an oligomeric/polymericmaterial with a molecular weight of 300 to 30,000, preferably from 350to 5,000 and more preferably from 400 to 750. Preferably, the Z moietyis a poly(ethoxyloxazoline) or a poly(N-vinylpyrrolidone) or apoly(alkyleneoxide) structure. It is also possible to use a Z compoundwhich is a copolymer of different compounds, e.g. a N-vinylpyrrolidoneand acrylamide. If such a copolymer is prepared, one of the monomers,e.g. the acrylamide is present only in minor amounts, that is less than10% by weight.

Monomer CC is preferably present in an amount of from 10 to 30% byweight, more preferably in the amount of 15 to 25% by weight of thetotal monomers.

The ratio of the microparticle component to the water dispersiblecomponent employed in the invention may vary over a wide range ofcompositions. For example, the adhesive composition may comprise from0.1 to 99.9 parts by weight of the microparticle composition andcorrespondingly from 99.9 to 0.1 parts by weight of thewater-dispersible polymer component. It has been discovered that certainnarrower ranges of these two components are preferred for specificutilities. For example, adhesive compositions comprising from about 50to 95 (preferably from 60 to 95) parts by weight of the microparticlecomponent and, correspondingly, from about 50 to 5 (preferably from 40to 5) parts by weight of the water-dispersible polymer component can beused to provide tapes that are especially useful in paper splicingapplications.

Adhesive compositions that comprise from about 10 to 50 (preferably from10 to 40) parts by weight of the microparticles and, correspondingly,from about 90 to 50 (preferably from 90 to 40) parts by weight of thewater-dispersible component are especially useful in closure systems forsurgical wrappers and in mammalian body coverings such as surgicalgowns, sheets, drapes and the like. In these applications the tapes canbe used without losing their pressure sensitive adhesive propertiesduring the sterilization process. It can also be used with asterilization indicator to indicate that a wrapped package has passedthrough a sterilization cycle. However, the wrappers and tapes thatutilize the adhesive of the invention can be laundered because theadhesive of the invention disperses in alkaline laundering solutions.Consequently, the adhesives do not need to be removed prior tolaundering.

Modifying Agents

The adhesive blend of the invention may optionally contain one, or more,modifying agents to impart or enhance desired characteristics related tothe preparation of the adhesive or to its application. Modifying agentsare generally employed at a level adequate to achieve the desired resultwithout affecting the pressure sensitive properties of the adhesive.Examples of useful modifying agents include, but are not limited to,thickening agents such as those selected from the group consisting ofalkali swellable, associative polymers, such as those sold under thenames UCAR®POLYPHOBE® (available from Union Carbide, Inc.); Alcogum™(available from Alco Chemical); Rheolate™ (available from Rheox);Acrysol™ (available from Rohm & Haas); and Carbopol™ (available from B.F. Goodrich).

Neutralizing agents, which are often employed in combination withthickening agents or carboxylic acid functional polymers, may also beused in the present invention. Such neutralizers include, but are notlimited to, those selected from the group consisting of metal ions, suchas sodium, potassium, calcium, magnesium, copper, aluminum, or zinc; andamines, such as ammonia, and organic amines such as n-hexylamine,monoethanol amine, hexamethylenediamine.

Other modifying agents which may be used to alter the properties of theadhesive blend include, but are not limited to, those selected from thegroup consisting of tackifying resins, plasticizers, pigments, fillers,flow control agents, and stabilizers.

Suitable materials useful as the flexible support or backing for thearticles of the invention include, but are not limited to, paper, latexsaturated paper, polymeric film, cellulose acetate film, ethyl cellulosefilm, cloth (i.e., woven or nonwoven sheeting formed of synthetic ornatural materials), metallic foil, and ceramic sheeting.

Examples of materials that can be included in the flexible supportinclude polyolefins (such as polyethylene, polypropylene (includingisotatic polypropylene), polystyrene, polyester, polyvinyl alcohol,poly(ethylene terephthalate), poly(butylene terephthalate),poly(caprolactam), poly(vinylidene fluoride), and the like. Commerciallyavailable backing materials useful in the invention include kraft paper(available from Monadnock Paper, Inc.); cellophane (available fromFlexel Corp.); spun-bond poly(ethylene) and poly(propylene), such asTyvek™ and Typar™ (available from DuPont, Inc.); and porous filmsobtained from poly(ethylene) and poly(propylene), such as Teslin™(available from PPG Industries, Inc.), and Cellguard™ (available fromHoechst-Celanese).

The flexible support may also comprise a release coated substrate. Suchsubstrates are typically employed when an adhesive transfer tape isprovided. Examples of release coated substrates are well known in theart. They include, by way of example, silicone-coated kraft paper andthe like.

Tapes of the invention may also incorporate a low adhesion backsize(LAB). Typically this LAB is applied to the tape backing surface that isopposite that bearing the pressure sensitive adhesive. LABS are known inthe art.

These and other examples of the invention are illustrated by thefollowing examples which should not be viewed as limiting in scope.Examples of the invention were prepared and examined for launderability,tack, adhesion, shear and repulpability. The following test methods wereemployed.

Test Methods Tack

In this test, a Delrin wheel (29 g in weight) with diameter of 8.13 cmand rim width of 1.9 cm is rolled down a plane having a length of 26.7cm and incline at 24° to a horizontal surface on which the tape to beevaluated is positioned, adhesive side up. The distance the wheel rollsalong the horizontal adhesive surface is measured, the tack beinginversely proportional to the distance the wheel travels.

Repulpability

Repulpability is measured according to TAPPI test UM-213. For adouble-faced tape, one 20 cm×2.54 cm strip is sandwiched between two 20cm×2.54 cm strips of blotter paper. For a single-faced tape, two 20cm×2.54 cm strips are adhered to blotter paper. The samples are cut intoapproximately 1.5 cm squares. A sufficient number of 1.5 cm squares ofblotter paper are then added to the tape/blotter paper combination toprovide a total test sample weight of 15 g. The test sample is thenplaced in a Waring Blender with 500 ml of room temperature tap water.After the blender has run for 20 seconds, it is stopped for 1 minutewhile the stock which has splashed up the sides and on the cover of theblender is washed back into the bottom with a water bottle. The blenderis then run for an additional 20 seconds, washed down as before, and runfor a final 20 seconds. The stock is then removed from the blender andmade into a handsheet on a sheet mold. The sheet is removed from themold, pressed between blotter paper for 90 seconds in a hydraulic press,dried, and examined for any particles of unrepulped tape. If two orfewer particles are present, the tape is considered to have passed thetest. The presence of one or two particles does not constitute failuresince these can be due to dirty equipment, or screens. When a materialfails the test, the particles will be dispersed throughout the sheet.

The foregoing test does not apply to tape products where, the backing isa material, such as polyester film, which does not lend itself torepulping. The dispersibility of the adhesive employed on such a backingmay be determined by testing the adhesive film either in the form of anadhesive transfer tape or as a layer on a water-dispersible supportlayer.

Laundering Test

A test specimen was produced by laminating a section of tape to betested to an untreated 50% cotton/50% polyester fabric (available fromStandard Textile Co., Cincinnati, Ohio as Barrier Supreme™). A 1.8 kg (4lb) rubber roller was used to laminate the tape to the fabric such thatthe microparticle-containing adhesive was left exposed. The testspecimen was then steam sterilized using a 134° C., 10-minutes,four-pulse prevacuum cycle and a one-minute steam dry time.

The test specimens were then laundered in a 60 lb. commercial washingmachine (Milnor washer, Model No. 36021BWE/AEA; Pillerin Milnor Corp.,Kenner, La.). The specimens went through a typical laundry cycle forsurgical linens including: (a) a three-minute cold alkaline break in a0.1% Paralate 55 GL11™ Commercial Liquid Laundry Alkali (Ecolab Inc.,St. Paul, Minn.); a three-minute cold water flush, an eight-minute hotbreak/suds wash using 0.1% of Paralate 55 GLW™ Commercial Liquid LaundryAlkali, and 0.05% Kindet™ Commercial Liquid Laundry Detergent (EcolabInc.); two three-minute hot water flushes; a three minute cold waterflush; a three-minute cold sour/soft rinse using 0.05% Tri Liquid Sour55GL™ Commercial Liquid Laundry Sour (Ecolab Inc.), and 0.05% TexSpecial Liquid™ Commercial Liquid Denim Lubricant/Softener (EcolabInc.), and a six minute extraction to remove excess liquid.

Each laundered specimen was inspected for a pass, meaning that noadhesive residue remained on the fabric, or for a fail, meaning thatthere was an adhesive residue on the fabric.

Adhesion

This test is for 180° peel adhesion to paper. A 3.175 cm strip of bondpaper is laminated to a 5 cm×12.5 cm stainless steel test panel using adouble-faced pressure sensitive tape. One end of a 2.54 cm×25 cm stripof sample tape is then laid over the laminated bond paper (if sample isdouble-faced tape, then 68 g/m² kraft paper backing is placed on oneadhesive side of the sample tape). Uniform adhesive contact is assuredby passing a 2 kg roller over the 12.5 cm sample length at a rate of30.6 mm/minute. The tape is then doubled back on itself and peeled fromthe bond paper surface at 30.5 cm/minute. The force to remove the tapeis recorded using an Instron Model 1122 operated at 21° C. and 50%relative humidity.

Shear Strength

A 2.54 cm×2.54 cm end portion of a 2.54 cm×15 cm strip of tape is used.If the tape has adhesive on only one surface, that adhesive face isadhered to a bright annealed steel test panel and rolled down with twopasses of a 2 kg roller. If the tape has adhesive on each surface, theadhesive whose shear strength is to be tested is adhered to the brightannealed steel panel and then a section of 68 g/m² supercalendared kraftpaper backing is laminated to the other adhesive face. The panel is thenclamped in a jig which is disposed at 2° to the vertical, so that the12.5 cm free end of the tape extends downward, at an angle of 178° tothe test panel, and a 1000 g weight is attached to the tape end. Thetime for the tape to separate from the panel is reported in to thenearest minute, the shear strength being directly related to the elapsedtime. Further details are found in the aforementioned Test Methods forPressure-Sensitive Tapes, Test PSTC-7. For tapes made with adhesive ofthis invention, it is desirable to have shear times as high as possible,preferably exceeding 1000 minutes, although an adhesive may besatisfactory if its shear time is as low as 40 minutes.

Abbreviations

The following abbreviations are used in the examples disclosed herein.

AA=acrylic acid

BA=butyl acrylate

BCEA=beta-carboxyethyl acrylate

PEOA=poly(ethylene oxide) monoacrylate, average molecular weight of 750

EOEA=2-ethoxy ethyl acrylate

EOEOEA=2-(2-ethoxy)ethoxy ethyl acrylate

HDDA=1,6-hexanediol diacrylate

IOA=isooctyl acrylate

MSA=microparticle adhesive

PC=water-dispersible polymeric component

PPG=poly(propylene glycol)

PAA=poly(acrylic acid)

PVA=poly(vinyl alcohol)

Repulp=Repulpability test

P=pass (Repulpability test)

F=fail (Repulpability test)

The parenthetical expression that introduces each preparation identifiesthe monomeric components and the weight percentages of each used in thepreparations.

Microparticle Preparation

Microparticle Component A (IOA:AA:PEOA/97:2:1)

4.8 g of AA, 2.4 g of PEOA and 1.13 g Lucidol™-70 (70% benzoyl peroxide;available from Elf Atochem) were dissolved in 232 g IOA. 0.75 gSiponate™ DS-10 (sodium dodecyl benzene sulfonate surfactant; availablefrom Rhone-Poulenc) was dissolved in 360 g of water. The IOA mixture wasthen added to the surfactant solution and emulsified using an Omni™Mixer until the droplet size was less than 5 microns. The 40% solidsemulsion was then charged to the 1 liter baffled reactor, heated to 65°C., degassed with N₂ allowed to react for 8 hours.

Microparticle Component B (IOA:AA:PEOA/89:1:10)

2.1 g of AA, 21 g of PEOA, 0.21 g of poly(ethylene oxide)₉dimethacrylate, and 0.99 g of Lucidol™ 70 were dissolved in 186.9 g ofIOA. 6 g of Standapol™. A surfactant (ammonium lauryl sulfate, Hercules)was dissolved in 390 g of water. The IOA mixture was added to thesurfactant solution, then emulsified using an Omni™ Mixer until thedroplet size was less than 5 micrometers. The emulsion was then chargedto a 1 liter indented resin flask, heated to 60° C., degassed withargon, and allowed to react for 18 hours.

Microparticle Component C (IOA:BA:AA:PEOA/79:17:1:3)

2.1 g of AA 8.4 g of PEOA, 39.9 g of BA, 0.25 g of HDDA, and 0.99 g ofLucidol™-70 were dissolved in 186.9 g of IOA. 6.5 g of Standapol™. Asurfactant (ammonium lauryl sulfate, Hercules) was dissolved in 390 g ofwater. The IOA mixture was added to the surfactant solution, thenemulsified using an Omni™ Mixer until the droplet size was less than 5micrometers. The emulsion was then charged to a 1 liter indented resinflask, heated to 65° C., degassed with argon, and allowed to react for22 hours.

Microparticle Component D (IOA:AA:HDDA/96:2:2)

4.2 g of AA, 4.2 g of HDDA, and 1.13 g of Lucidol™-70 were dissolved in230 g of IOA. 0.75 g of sodium dodecyl benzene sulfonate surfactant wasdissolved in 360 g of water. The IOA mixture was added to the surfactantsolution, then emulsified using an Omni™ Mixer until the droplet sizewas less than 5 micrometers. The emulsion was then charged to a 1 literindented resin flask, heated to 65° C., degassed with argon, and allowedto react for 12 hours. The resulting microparticles were non-tacky.

Microparticle Component E (100% IOA)

The microparticles were prepared in a 1 liter indented resin flask thatwas charged with 450 ml of deionized water and 4 g of Standapol™. Theaqueous solution was stirred at 400 rpm, heated to 70° C., and degassedwith argon. 150 g of IOA and 0.71 g of Lucidol™-70 were added to the hotaqueous surfactant solution. The temperature was then reduced to 65° C.,and the mixture allowed to react for 22 hours. The approximate averageparticle diameter was 33 microns as determined by optical microscopy.

Water-Dispersible Polymeric Component Preparation

PC-1 (EOEOEA:AA/80:20)

1217 g deionized water and 0.39 g potassium persulfate were added to athree liter flask equipped with condenser, agitator, and nitrogen purgeline. The mixture was heated to 76° C., purged with N₂ and, agitated at150 rpm. Charges I, II, and III were prepared. Charge I contained 13.5 gMazon™ SAM-211, commercially available from PPG/Mazer Chemicals,dissolved in 100 g deionized water. Charge II contained 0.39 g potassiumpersulfate dissolved in 50 g deionized water. Charge III contained 240 gEOEOEA, 60 g AA, and 0.09 g t-dodecyl mercaptan. Charge I and 75.0 g ofCharge III were added to the flask and reacted for 30 minutes. Theremaining portion of Charge III and all of Charge II were then addedincrementally to the flask over a 1-2.5 hour period. The contents of theflask were then reacted for an additional 35 minutes after the lastcharge of ingredients. The emulsified contents were cooled and drainedfrom the flask. They had a pH=3.32, a Brookfield viscosity=5 cps, andparticle size=182 μ.

PC-2 (EOEA;AA/85:15)

800 g deionized water and 0.39 g potassium persulfate were added to atwo liter flask equipped with condenser, agitator, and nitrogen purgeline. The contents were heated to 76° C., purged with N₂ and agitated at300 rpm. Charges I, II, and III were prepared. Charge I contained 13.5 gMazon™ SAM-211 dissolved in 100 g deionized water. Charge II contained0.39 g potassium persulfate dissolved in 50 g deionized water. ChargeIII contained 255 g EOEOEA, 45 g and 0.09 g t-dodecyl mercaptan. ChargeI and 75.0 g of Charge III were added to the flask and reacted for 30minutes. The remaining part of Charge III and all of Charge II were thenadded incrementally over a 1-2.5 hour period. After the last additionthe contents of the flask were reacted for an additional 35 minutes. Theemulsified contents were cooled and drained from the flask. The polymerhad a particle size=94.3 μ.

PC-3 (EOEOEA:BA:AA/75:15:10)

800 g deionized water and 0.39 g potassium persulfate were added to atwo liter flask equipped with condenser, agitator, and nitrogen purgeline and heated to 76° C., purged with N₂ and agitated at 300 rpm.Charges I, II, and III were prepared. Charge I contained 13.5 g Mazon™SAM-211 dissolved in 100 g deionized water. Charge II contained 0.39 gpotassium persulfate dissolved in 50 g deionized water. Charge IIIcontained 225 g EOEOEA, 45 g BA, 30 g AA, and 0.09 g t-dodecylmercaptan. Charge I and 75.0 g of Charge III were added to the flask andreacted for 30 minutes. The remaining portion of Charge III and all ofCharge II were added incrementally over a 1-2.5 hour period. Theingredients were reacted for an additional 35 minutes after the lastcharge. The emulsified contents were cooled and drained from the flask.The polymer had a particle size=236μ.

PC-4 (EOEOEA:BA:AA/70:15:15)

1672 g deionized water, 20.9 g Mazon™ SAM-211, and 2.1 g potassiumpersulfate were added to a three liter flask equipped with condenser,agitator, and nitrogen purge line, heated to 76° C., purged with N₂ andagitated at 200 rpm. A premix containing 292.6 g EOEOEA, 62.7 g BA, 62.7g AA, and 0.30 g t-dodecyl mercaptan were prepared and add to the flaskthrough a dropping funnel over 5 hour period. The emulsified product wasthen cooled and drained from the flask. The polymer had a pH=2.46, aBrookfield viscosity=4.5 cps and a particle size=108μ.

PC-5 (EOEOEA:BA:AA/50:35:15)

1672 g deionized water, 20.9 g Mazon™ SAM-211, and 2.1 g potassiumpersulfate were added to a three liter flask equipped with condenser,agitator, and nitrogen purge line, heated to 76° C., purged with N₂ and,agitated at 200 rpm for a premix containing 209 g EOEOEA, 146.3 g BA,62.7 g AA, and 0.21 g t-dodecyl mercaptan was prepared and added to theflask through a dropping funnel over 6 hour period. The emulsifiedreaction product was then cooled and drained from the flask. It had apH=2.55, a Brookfield viscosity =4.5 cps, and a particle size=91.0μ.

PC-6 (EOEOEA:BCEA/82:18)

2000 g deionized water and 0.65 g potassium persulfate were added to athree liter flask equipped with condenser, agitator, and nitrogen purgeline, heated to 76° C., purged with N₂ and, agitated at 150 rpm. ChargesI, II, and III were prepared. Charge I contained 22.5 g Mazon™ SAM-211dissolved in 100 g deionized water. Charge II contained 0.65 g potassiumpersulfate dissolved in 50 g deionized water. Charge III contained 410 gEOEOEA, 90 g BCEA, and 0.15 g t-dodecyl mercaptan. Charge I and 75.0 gof Charge III were added to the flask and reacted for 30 minutes. Theremaining portion of Charge III and all of Charge II were then addedover a 1-5 hour period. The contents of the flask were reacted for anadditional 35 minutes after the last charge. The emulsified reactionproduct was cooled and drained from the flask. It had a pH=4.47, aBrookfield viscosity=1.5 cps, and a particle size=146μ.

PC-7 (EOEOEA:BA:AA/60:20:20)

1217 g deionized water and 0.39 g potassium persulfate were added to athree liter flask equipped with condenser, agitator, and nitrogen purgeline, and heated to 76° C., purged with N₂ and, agitated at 150 rpm.Charges I, II, and III were prepared. Charge I contained 13.5 g Mazon™SAM-211 dissolved in 100 g deionized water. Charge II contained 0.39 gpotassium persulfate in 50 g dissolved in deionized water. Charge IIIcontained 180 g EOEOEA, 60 g BA, 60 g AA, and 0.09 g t-dodecylmercaptan. Charge I and 75.0 g of Charge III were added to the flask andreacted for 30 minutes. The remaining Charge III and all of Charge IIwere then added over a 1-2.5 hour period. The contents of the flask werethen reacted for an additional 30 minutes after which they were cooledand drained. The emulsified reaction product had a particle size=101 μ,and Brookfield viscosity=5.0 cps.

PC-8 (EOEOEA:IOA:/β-CEA/50:17:33)

1220 g deionized water and 0.39 g potassium persulfate were added to athree liter flask equipped with condenser, agitator, and nitrogen purgeline, heated to 76° C., purged with N₂ and, agitated at 150 rpm. ChargesI, II, and III were prepared. Charge I contained 13.5 g Mazon™ SAM-211dissolved in 100 g deionized water. Charge II contained 0.39 g potassiumpersulfate dissolved in 50 g deionized water. Charge III contained 150 gEOEOEA, 51.0 g IOA, 99.0 g BECE, and 0.09 g t-dodecyl mercaptan. ChargeI and 75.0 g of Charge III were added to the flask and reacted for 30minutes. The remaining Charge III and all of Charge II were then addedover a 1-3 hour period. The contents of the flask were reacted foradditional 35 minutes. The emulsified reaction product was cooled anddrained from the flask. It had a pH =3.32, a Brookfield viscosity=3 cps,and a particle size=210μ.

PC-9 (EOEOEA:AA/95:5)

800 g deionized water and 0.39 g of potassium persulfate were added to atwo liter split resin flask equipped with condenser, agitator, andnitrogen purge line, and heated to 76° C. and, agitated at 150 rpm. Theflask was purged with 1 liter per minute N₂. Charges I, II, and III wereprepared. Charge I contained 15.0 g Mazon™ SAM-211, dissolved in 100 gdeionized water. Charge II contained 0.39 g potassium persulfatedissolved in 50 g deionized water. Charge III contained 285 g EOEOEA,available from Sartomer Chemical Co., 15 g AA, and 0.09 g t-dodecylmercaptan. Charge I and 75.0 g of Charge III were added to the flask andreacted for 30 minutes. The remaining Charge III and all of Charge IIwere then added over a 1-2.5 hour period. The contents of the flask werereacted for an additional 30 minutes after which the emulsified reactionproduct was cooled and drained from the flask.

PC-10 (IOA:AA/85:15)

800 g deionized water and 0.39 g potassium persulfate were added to atwo liter split resin flask equipped with condenser, agitator, andnitrogen purge line. The reactants were heated to 76° C., purged with N₂(1 l/min) and, agitated at 150 rpm. Charges I, and II, were prepared.Charge I contained 13.5 g Mazon™ SAM-211 dissolved in 100 g deionizedwater. Charge II contained 225 g IOA, 45 g AA, and 0.09 g t-dodecylmercaptan. Charge I and 75 g of Charge II were added to the flask andreacted for 30 minutes at 76° C. The remaining portion of Charge II wasthen added over a 2 hour period. The contents of the flask were thenreacted for an additional 30 minutes. The resulting emulsified reactionproduct was then cooled and drained from the flask. It had a solidscontent of 26.8% by weight and a particle size of 128 nanometers.

PC-11 (EOEOEA:AA/90:10)

2403 g deionized water and 1.17 g potassium persulfate were added to afive liter flask equipped with condenser, agitator, and nitrogen purgeline. The reactants were heated to 76° C., purged with N₂ and, agitatedat 150 rpm. Charges I, II, and III were prepared. Charge I contained40.5 g Mazon™ SAM-211 dissolved in 297.0 g deionized water. Charge IIcontained 1.17 g potassium persulfate dissolved in 100 g deionizedwater. Charge III contained 810 g EOEOEA, 90 g AA, and 0.27 g t-dodecylmercaptan. Charge I and 300 g of Charge III were added to the flask andreacted for 30 minutes. The remaining Charge III and all of Charge IIwere then added over a 1-2.5 hour period. The contents of the flask werethen reacted for an additional 30 minutes. The resulting emulsifiedreaction product was then cooled and drained from the flask.

PC-12 (EOEOEA:AA/90:10)

62.3 kg deionized water and 21.2 g potassium persulfate to a 25 gallon(95 1) glass-lined reactor and heated to 76° C. The contents of thereactor were agitated at 75 rpm and purged with N₂. Charges I and IIwere then prepared. Charge I contained 1.6 kg AA, 735 g Mazon™ SAM-211,14.7 kg EOEOEA, and 4.9 g t-dodecyl mercaptan. Charge II contained 5.3kg deionized water and 21.2 g potassium persulfate. 4.3 kg of Charge Iwere added to the reactor and reacted for 30 minutes. The remainingCharge I and all of Charge II were then added to the reactor over a1.5-2 hour period. The contents of the reactor were reacted for anadditional one hour. The resulting emulsified reaction product wascooled and drained from the reactor. It had a particle size=228 μ, and aBrookfield viscosity=4 cps.

EXAMPLES 1-10

Adhesive tape samples employing only Microparticle Components A-E wereprepared by mixing the microparticles with 1% by weight of anassociative, alkali-swellable thickener, (UCAR Polyphobe™ 104, availablefrom Union Carbide) and neutralized with potassium hydroxide andpoly(oxypropylene)triamine to a pH of 7. The adhesive was coated on arelease surface and dried in a oven at 79° C. for three minutes This waslaminated to "Crystex" tissue paper to provide a single sidedconstruction. To obtain a double sided construction, adhesive was coatedonto the opposite side of the single sided sample and dried in a similarmanner. Testing was conducted after removal of the release liner.

Adhesive tape samples for Examples 1-10 were prepared by mixing theMicroparticle Component A with the desired water soluble, ordispersible, polymeric component, then thickened, neutralized, andcoated in the same manner as used with the tapes made from MicroparticleComponents A-E above. The water soluble, or dispersible, polymericcomponents employed were an organic phosphate ester, Gafac® PE-510,available from International Specialty Products; poly(vinyl alcohol),PVA, with a molecular weight of 8×10⁵ g/mol; poly(acrylic acid), PAA,with a molecular weight of 2×10⁵ g/mol; poly(ethylene oxide), PEO, witha molecular weight of 10⁶ g/mol; ethoxylated alkylphenols, Igepal®CA-520, CA-630 and CO-630, available from International SpecialtyProducts; poly(alkylene glycol), Sannix® SP-750, available from SanyoChemical Industries; and poly(propylene glycol), PPG, with a molecularweight of 400 g/mol.

These examples show that addition of a water soluble, or dispersible,polymeric component to a microparticle adhesive provides enhancedperformance in tack while maintaining repulpability. These results arerecorded in Table 1.

                  TABLE 1                                                         ______________________________________                                                                               Repulp                                                                 Tack   Test                                   Example Polymeric Component                                                                          % P.C.   (mm)   (P/F)                                  ______________________________________                                        Control None           0        80     P                                              (All Microparticle                                                            Component A)                                                          1       Gafac ® PE-510                                                                           0.5      15     P                                      2       Gafac ® PE-510                                                                           1.0      20     P                                      3       PVA            1.0      33     P                                      4       PAA            1.0      38     P                                      5       PEO            1.0      29     P                                      6       Igepal ® CA-520                                                                          2.5      48     P                                      7       Igepal ® CA-630                                                                          2.5      47     P                                      8       Igepal ® CO-630                                                                          2.5      36     P                                      9       Sannix ® SP-750                                                                          5.0      30     P                                      10      PPG            5.0      33     P                                      ______________________________________                                    

Examples 11-21

Examples 11-21 were prepared in the same manner as Examples 1-10 usingMicroparticle Component A and the Polymeric Component indicated in Table2. However, no thickening agent was added.

These examples show that when the water soluble, or dispersible,polymeric component added is a PSA, the adhesion performance is improvedin all cases, as is the tack in most cases, while maintainingrepulpability. The results are recorded in Table 2.

                  TABLE 2                                                         ______________________________________                                               Polymeric   PC Com-        Repulp                                             Component   ponent   Tack  Test  Adhesion                              Example                                                                              (PC)        (%)      (mm)  (P/F) (N/cm)                                ______________________________________                                        Control                                                                              None (All    0       80    P     3.6                                          Microparticle                                                                 Component A)                                                           11     PC-1        22       56    P     6.9                                   12     PC-2        22       17    P     8.0                                   13     PC-3        22       20    P     7.3                                   14     PC-4        22       123   P     7.1                                   15     PC-5        22       79    P     6.9                                   16     PC-6        22       14    P     8.4                                   17     PC-7        13       38    P     6.3                                   18     PC-8        13       20    P     7.1                                   19     PC-1        13       33    P     6.4                                   20     PC-9        13       21    P     5.8                                   21     PC-10       22       32    P     6.0                                   ______________________________________                                    

Examples 22-33

In Examples 22-33 the water soluble, or dispersible, polymeric componentused was PC-11 and the Microparticle Component was MicroparticleComponent A. Example 22 was prepared in the same manner as Example 1;and Examples 23-32 were prepared in the same manner as Example 11.Example 33 was neutralized as described in Example 11.

These examples demonstrate the properties of the invention over a widerange of polymeric component concentrations. The results show enhancedperformance in tack and adhesion and in shear (in most cases), whilerepulpability is maintained, with respect to Control A as recorded inTable 3.

                  TABLE 3                                                         ______________________________________                                                                                RT                                           Polymeric           Repulp       Shear                                        Component   Tack    Test  Adhesion                                                                             Adhesion                              Example                                                                              (%)         (mm)    (P/F) (N/cm) (min)                                 ______________________________________                                        Control                                                                              0 (All      80      P     3.6    1330                                  A      Microparticle                                                                 Component A)                                                           22     5           62      P     5.4    2800+                                 23     9           37      P     5.4    2800+                                 24     13          24      P     5.4    2800+                                 25     23          21      P     6.1    2800+                                 26     31          18      P     6.1    2800+                                 27     38          18      P     5.7    2800+                                 28     43          22      P     6.1    2020                                                                          (Shear)                               29     47          22      P     6.5    1650                                                                          (Shear)                               30     60          35      P     5.7    130                                                                           (Shear)                               31     75          33      P     5.9    76                                                                            (Shear)                               32     90          39      P     5.9    57                                                                            (Shear)                               33     100         31      P     7.8    130                                          (All PC-11)                      (Shear)                               ______________________________________                                    

Control A popped off after 1330 minutes. Examples 28, 29 and 33 shearedat the indicated time.

Examples 34-38

These Examples show the effect of combining a water-dispersible,polymeric component, consisting of a copolymer of EOEOEA and acrylicacid at various ratios, with different types of microparticle adhesives.Examples 34, 35, 36, 37, and 38 (with a polymeric component) wereprepared in the same manner as Example 11.

Control B and Example 34 compare microparticle compositions whichcontain 10% PEOA. Control B employs no polymeric component. Example 34employs 22% by weight of PC-5. Incorporation of PC-5 results in improvedadhesion and repulpability as shown in Table 4.

                  TABLE 4                                                         ______________________________________                                                            PC            Repulp                                               Microparticle                                                                            Com-    Tack  Test  Adhesion                              Example  Component  ponent  (mm)  (P/F) (N/cm)                                ______________________________________                                        Control B                                                                              B          --      19    F     5.8                                   34       B          PC-5    35    P     6.7                                   ______________________________________                                    

Control C and Example 35 compare microparticle compositions whichcontain PEOA and butyl acrylate. Control C employs no polymericcomponent. Example 35 contains 22% by weight PC-1. Incorporation of PC-1results in improved adhesion and repulpability as shown in Table 5.

                  TABLE 5                                                         ______________________________________                                                            PC            Repulp                                               Microparticle                                                                            Com-    Tack  Test  Adhesion                              Example  Component  ponent  (mm)  (P/F) (N/cm)                                ______________________________________                                        Control C                                                                              C          --       33   F     3.7                                   35       C          PC-1    180   P     5.6                                   ______________________________________                                    

Control D and Examples 36 and 37 compare microparticle compositionswhich are tack free. Control D employs no polymeric component. Examples36 and 37 employ 33 and 43 weight percent PC-4, respectively.Incorporation of PC-4 results in improved tack and adhesion, whilemaintaining repulpability as shown in Table 6.

                  TABLE 6                                                         ______________________________________                                                            PC            Repulp                                               Microparticle                                                                            Com-    Tack  Test  Adhesion                              Example  Component  ponent  (mm)  (P/F) (N/cm)                                ______________________________________                                        Control D                                                                              D          --      ***   P     ***                                   36       D          PC-4    150   P     1.3                                   37       D          PC-4    150   P     2.9                                   ______________________________________                                         ***tack free, unable to test                                             

Control E and Example 38 compare microparticle compositions which arelarge in size, diameter=33 micrometers, relative to all other Examplesdisclosed herein in which the diameter is approximately 3 micrometers.Control E employs no polymeric component. Example 38 employed 43 percentby weight of PC-12. Incorporation of PC-12 results in improvement intack and repulpability.

                  TABLE 7                                                         ______________________________________                                                            PC            Repulp                                               Microparticle                                                                            Com-    Tack  Test  Adhesion                              Example  Component  ponent  (mm)  (P/F) (N/cm)                                ______________________________________                                        Control E                                                                              E          --      170   F     6.1                                   38       E          PC-12   130   P     4.1                                   ______________________________________                                    

Examples 39-42

Pressure sensitive adhesive tapes of the invention were prepared,laminated to untreated 50% cotton/50% polyester fabric (BarrierSupreme™) and laundered as described in the Laundering Test. The backingemployed in the tape was "Crystex" tissue paper. The adhesivecompositions tested and the results obtained are set out in Table 8.

                  TABLE 8                                                         ______________________________________                                                             Water-Dispersible                                        Microparticle Component                                                                            Component                                                Example Mat'l.   Parts by Weight                                                                           Mat'l.                                                                              Parts by Weight                            ______________________________________                                        39      A        78          PC-6  22                                         40      A        87          PC-7  13                                         41      A        87          PC-1  13                                         42      A        87          PC-8  13                                         ______________________________________                                    

All samples showed no evidence of residue on the laundered fabric.

Example 43

A water-dispersible polymer was prepared. First, amono-methoxypolyethyl(eneglycol)acrylate monomer with a molecular weightof 750 was prepared by Fischer esterification of Carbowax™ 750 (UnionCarbide). One hundred parts of the Carbowax™ 750 and 100 parts oftoluene were introduced to a flask which was equipped with a Dean-Starkcondenser and a stirrer. The solution was heated to reflux-temperaturefor two hours. 11.3 parts of acrylic acid, 4.5 parts of p-toluenesulfonic acid, 3,000 ppm of Irganox™ PS 800 (Ciba-Geigy) and 500 ppmphenothiazine were added into this mixture. The solution was heated toreflux-temperature for another 16 hours. After cooling down to roomtemperature, excess acid was neutralized with 4.5 parts of calciumhydroxide. The formed precipitate was filtered off. Subsequently thetoluene was evaporated under reduced pressure to yield a solid 100%acrylate monomer.

A water-dispersible pressure sensitive adhesive polymers was prepared bycharging butyl acrylate (BA), BCEA (commercially available as a mixtureof 20 weight % acrylic acid, 40 weight % BCEA, 40 weight % other acrylicacid oligomers from Rhone Poulenc), the mono-methoxypoly(ethyleneglycol)acrylate monomer to a one quart bottle containing a solvent mixture ofethyl acetate, methanol and isopropanol, and 0.51 gramsazobisisobutyronitrile. The monomer charge comprised between 32 and 34%of the polymerization mixture. The mixture was deoxygenated by purgingwith one liter per minute nitrogen for two minutes. The bottle wassealed and placed in a rotating water bath at 55° C. for 24 hours toeffect essentially complete polymerization. The inherent viscosity (IV)of the resultant polymer was then measured in 2-butanone at 27.5° C.Neutralizing agent (86.8% pure KOH, 1.25 neutralization equivalentsbased upon 100% pure KOH) in a 3.57N 50:50 methanol:water (V/V) solutionwas blended into the adhesive polymer. Microparticles (A) were thenmixed into the adhesive polymer to give a final ratio of 20 gmicroparticles to 100 g adhesive polymer (i.e., 16.7% microparticles byweight).

The resultant neutralized microparticle-containing pressure sensitiveadhesive composition was applied to a 29 pound basis weight Kraft paper(M-2383) Smooth Crepe Semi-Bleached Kraft Saturating Paper from MosineePaper Corporation of Mosinee, Wis.) to form a closure tape as describedbelow.

The pressure sensitive adhesives in the solvent system were coated onthe Kraft paper at 0.68 grams per 154.8 cm² (24 in²) using a standardlaboratory knife coater, with drying for 15 minutes in a forced air ovenat 100° C.

Table 9 shows the initial adhesion, post-sterilization adhesion,pre-sterilization wrapper closure (T(0)), post-sterilization wrapperclosure (T(A)), and dispersibility of the closure tapes of Example 43and Comparative Example 1 on a fluorochemically-treated polyesterwrapper. The following test procedures were utilized.

Initial Adhesion to Treated Drape Wrappers

Samples of a fluorochemically-treated polyester drape (available fromStandard Textile Co., Cincinnati, Ohio as WrapPel™ T) were cut into 3.81cm by 10.16 cm strips and adhered with #410 double coated tape availablefrom the 3M Co.) to a 5.08 cm by 12.2 cm steel plate. Example closuretapes of the invention (2.54 cm by 10.16 cm) were applied to the drapeand were rolled twice with a 2 kg rubber roller.

One end of each of the plate was placed in the jaws on an Instron Model1122 tensile tester (Instron Corp., Canton, Mass.), while one end of theclosure tape was adhered to the opposing set of jaws of the tensiletester to allow removal of the tape from the drape at essentially a 180°peel angle. The rate of jaw movement was 30.48 era/minute and thetensile tester recorded the force required to separate the tape laminatefrom the drape. The results were recorded in Newtons per 2.54 cm (N/2.54cm). The initial adhesion measurement derives from the fact that thedwell time of the tape on the drape was short; i.e., the example tapewas applied and peeled without a long residence time (i.e., less than 5minutes) in between, and sterilization had not yet taken place.

Post-sterilization Adhesion to Treated Drape

The same method as the initial adhesion test was used for this test,except that prior to testing, the example closure tapes were steamsterilized at a setting of 273° F. (134° C.), in a 10 minute gravitycycle with a three minute steam dry time. The sterilizer used was aBarnstead Model GLS-10D (MDT Biologic Co., Rancho Dominquez, Calif.). Inaddition, the laminate was allowed to cool at room temperature for aminimum of 4 hours before peel testing. The results were recorded inN/2.54 cm.

Static Shear Strength

The tapes were tested for static shear strength as follows. A stainlesssteel plate was washed with diacetone and wiped with a tissue (KIM-WIPE)and then washed again with heptane followed by wiping with a tissue. Theheptane wash was repeated two more times. A length of the tape wasapplied to the WraPel™ T drape material to provide a 2.54 cm by 2.54 cmbond area. The remainder of the tape hung over the edge and was doubledback to form a loop. A 2 kg roller was passed back and forth over thebond area once in the length direction of the tape. A 250 g weight washung from the loop and the resulting assembly hung vertically in a roommaintained at 20° C. and 50% relative humidity. The time to failure(i.e., the time for the tape to fall from the stainless steel plate) wasmeasured.

                  TABLE 9                                                         ______________________________________                                        Property                                                                      ______________________________________                                        Initial Adhesion        229 N/2.54 cm                                         Post Sterilization Adhesion (N/2.54 cm)                                                               88 N/2.54 cm                                          Static Shear            88 min                                                Dispersibility          Pass                                                  ______________________________________                                    

While this invention has been described in terms of specific embodimentsit should be understood that it is capable of further modification. Theclaims herein are intended to cover those variations one skilled in theart would recognize as the chemical equivalent of what has beendescribed here.

What is claimed is:
 1. A pressure sensitive adhesive tape comprising alayer of a water-dispersible, normally tacky pressure sensitive adhesivewhich comprises a blend of:A) a polymeric, elastomeric, solventinsoluble but solvent dispersible microparticle component, and B) awater dispersible polymeric component,on at least one surface of aflexible support, wherein said pressure sensitive adhesive is repulpablewhen tested according to TAPPI test UM-213.
 2. A pressure sensitiveadhesive tape according to claim 1 wherein said layer of normally tackypressure sensitive adhesive is strippably bonded to said flexiblesupport.
 3. A pressure sensitive adhesive tape according to claim 1wherein said layer of normally tacky pressure sensitive adhesive isessentially permanently bonded to said flexible support.
 4. A pressuresensitive adhesive tape according to claim 3 wherein said flexiblesupport is selected from the group consisting of polymeric film, paper,cellulose acetate film, ethyl cellulose film, woven and non wovensheeting, metallic foil, and ceramic sheeting.
 5. A pressure sensitiveadhesive tape according to claim 4 wherein said tape is repulpable.
 6. Apressure sensitive adhesive tape according to claim 4 wherein saidflexible support is paper.
 7. A pressure sensitive adhesive tapeaccording to claim 4 wherein said flexible support is selected from thegroup consisting of woven and non-woven fibrous sheeting.
 8. A pressuresensitive adhesive tape according to claim 4 wherein said flexiblesubstrate is a polymeric film.
 9. A pressure sensitive adhesive tapeaccording to claim 1 wherein said flexible support is repulpable, saidlayer of normally tacky pressure sensitive adhesive is on at least aportion of a first side of said support layer, and a layer of a releaseagent is on at least a portion of a second side of said flexible supportlayer, said second side of said flexible support layer being oppositesaid first side of said flexible support layer.
 10. A repulpable,pressure sensitive adhesive tape comprising a layer of a normally tackypressure sensitive adhesive, said pressure sensitive adhesive comprisinga polymeric, elastomeric, solvent insoluble but solvent dispersiblesuspension polymerized, microparticle component and a water-dispersiblepolymeric component, wherein said pressure sensitive adhesive isrepulpable when tested according to TAPPI test UM-213.
 11. Awater-dispersible pressure sensitive adhesive tape according to claim 10comprising from about 0.1 to 99.9 parts by weight of said microparticlecomponent and from about 99.9 to 0.1 parts by weight of saidwater-dispersible polymeric component.
 12. A water-dispersible pressuresensitive adhesive tape according to claim 11 comprising from 10 to 95parts by weight of said microparticle component and correspondingly from90 to 5 parts by weight of said water-dispersible polymeric component.13. A repulpable pressure sensitive adhesive tape according to claim 12comprising from 50 to 95 parts by weight of said microparticle componentand correspondingly from 50 to 5 parts by weight of saidwater-dispersible polymeric component.
 14. A repulpable pressuresensitive adhesive tape according to claim 13 comprising from 60 to 95parts by weight of said microparticle component and correspondingly from40 to 5 parts by weight of said water-dispersible polymeric component.15. A launderable pressure sensitive adhesive tape according to claim 12comprising from 10 to 50 parts by weight of said microparticle componentand correspondingly from 90 to 50 parts by weight of saidwater-dispersible polymeric component.
 16. A launderable pressuresensitive adhesive tape according to claim 15 comprising from 10 to 40parts by weight of said microparticle component and from 90 to 60 partsby weight of said water-dispersible component.
 17. A pressure sensitiveadhesive tape according to claim 11 wherein said microparticle componentis pressure sensitive.
 18. A pressure sensitive adhesive tape accordingto claim 11 wherein said water-dispersible polymeric component ispressure sensitive.
 19. A pressure sensitive adhesive tape comprising alayer of a normally tacky pressure sensitive adhesive which isrepulpable when tested according to TAPPI test UM-213, said adhesivecomprising(A) from 10 to 95 parts by weight of a microparticle componentwhich comprises the emulsion polymer of (1) 100 parts by weight or lessof at least one free radically polymerizable monomer selected from thegroup consisting of alkyl acrylate esters, alkyl methacrylate esters,vinyl esters and mixtures thereof;(2) 0 to 30 parts by weight of atleast one polar monomer copolymerizable with the free radicallypolymerizable monomer of part A(1); and (3) 0 to 40 parts by weight ofat least one hydrophilic oligomer or polymer copolymerizable with eitherof the free radically polymerizable monomer A(1) and the polar monomerA(2), andcorrespondingly from 90 to 5 parts by weight of a (B)water-dispersible polymer component which comprises the polymer of: (1)50 to 98 parts by weight of a poly(alkoxyalkyl) acrylate; andcorrespondingly (2) 50 to 2 parts by weight of a carboxylic acid.
 20. Apressure sensitive adhesive tape according to claim 19 comprising from50 to 95 parts by weight of said microparticle component andcorrespondingly from 50 to 5 parts by weight of said water-dispersiblepolymeric component.
 21. A pressure sensitive adhesive tape according toclaim 12 comprising from 60 to 95 parts by weight of said microparticlecomponent and correspondingly from 40 to 5 parts by weight of saidwater-dispersible polymeric component.
 22. A pressure sensitive adhesivetape according to claim 12 comprising from 10 to 50 parts by weight ofsaid microparticle component and correspondingly from 90 to 50 parts byweight of said water-dispersible polymeric component.
 23. A pressuresensitive adhesive tape according to claim 22 comprising from 10 to 40parts by weight of said microparticle component and correspondingly from90 to 60 parts by weight of said water-dispersible polymeric component.24. A fabric bearing the pressure sensitive adhesive tape of claim 23.25. A fabric according to claim 24 in the form of a mammalian bodycovering.
 26. A pressure sensitive adhesive tape according to claim 23in the form of a sterilization indicator tape.
 27. A splice comprisingfirst and second repulpable sheets joined together by a pressuresensitive adhesive tape according to claim
 10. 28. An article ofmanufacture comprising a flexible support having a portion of a layer ofa normally tacky pressure sensitive comprising a layer of awater-dispersible, normally tacky pressure sensitive adhesive whichcomprises a blend of:A) a polymeric, elastomeric, solvent insoluble butsolvent dispersible microparticle component, and B) a water-dispersiblepolymeric component,said adhesive being essentially permanently bondedto at least a portion of one surface of said flexible support, and beingrepulpable when tested according to TAPPI test UM-213.
 29. An article ofmanufacture according to claim 28 further comprising indicia thereon.30. A container having an article of manufacture according to claim 28secured thereto by said normally tacky pressure sensitive adhesive. 31.An article of manufacture comprising a flexible support having a layerof a normally tacky pressure sensitive adhesive comprising a layer of awater-dispersible, normally tacky pressure sensitive adhesive whichcomprises a blend of:A) a polymeric, elastomeric, solvent insoluble butsolvent dispersible microparticle component, and B) a water-dispersiblepolymeric component,said adhesive being strippably bonded to at least aportion of one surface of said flexible support support, and beingrepulpable when tested according to TAPPI test UM-213.
 32. A pressuresensitive adhesive tape comprising a layer of a pressure sensitiveadhesive comprising the emulsion polymerization product of:A) from about50 to 98 parts by weight of a poly(alkoxyalkyl)acrylate, andcorrespondingly B) from about 50 to 2 parts by weight of carboxylicacid, and C) from about 0 to 40 parts by weight of an essentiallywater-insoluble alkyl acrylate, and D) from about 0 to 6 parts by weightof an emulsion monomer copolymerizable with either of saidpoly(alkoxyalkyl)acrylate or said carboxylic acid,on at least a portionof at least one surface of a flexible support, wherein said pressuresensitive adhesive is repulpable when tested according to TAPPI testUM-213.
 33. A pressure sensitive adhesive tape according to claim 32wherein said layer of normally tacky pressure sensitive adhesive polymeris strippably bonded to said flexible support.
 34. A pressure sensitiveadhesive tape according to claim 32 wherein said layer of normally tackypressure sensitive adhesive polymer is essentially permanently bonded tosaid flexible support.
 35. A pressure sensitive adhesive tape accordingto claim 34 wherein said flexible support is selected from the groupconsisting of polymeric film, paper, cellulose acetate film, ethylcellulose film, woven and non woven sheeting, metallic foil, and ceramicsheeting.
 36. A pressure sensitive adhesive tape according to claim 32wherein said tape is repulpable.
 37. A pressure sensitive adhesive tapeaccording to claim 36 wherein said flexible support is paper.
 38. Apressure sensitive adhesive tape according to claim 32 wherein saidflexible support is selected from the group consisting of woven andnon-woven fibrous sheeting.
 39. A pressure sensitive adhesive tapeaccording to claim 32 wherein said flexible substrate is a polymericfilm.
 40. A pressure sensitive adhesive tape according to claim 32wherein said flexible support is repulpable, said layer of a normallytacky pressure sensitive adhesive polymer is on at least a portion afirst side of said flexible support layer, and a layer of a releaseagent on at least a portion of a second side of said flexible supportlayer, said second side of said flexible support layer being oppositesaid first side of said flexible support layer.
 41. A repulpable,pressure sensitive adhesive tape comprising a layer of a normally tackypressure sensitive adhesive which is repulpable when tested according toTAPPI test UM-213, said pressure sensitive adhesive polymer comprisingthe emulsion polymerization product of:A) from about 50 to 98 parts byweight of a poly(alkoxyalkyl)acrylate, and correspondingly B) from about50 to 2 parts by weight of carboxylic acid, and C) from about 0 to 40parts by weight of an essentially water-insoluble alkyl acrylate, and D)from about 0 to 6 parts by weight of an emulsion monomer copolymerizablewith either of said poly(alkoxyalkyl)acrylate or said carboxylic acid.42. A pressure sensitive adhesive tape according to claim 11 whereinsaid microparticle component is tack free.
 43. A pressure sensitiveadhesive tape comprising a flexible support and a layer of awater-dispersible, normally tacky pressure sensitive adhesive whichcomprises a blend of:A) a polymeric, elastomeric, solvent insoluble butsolvent dispersible microparticle component, and B) a water-dispersiblepolymer component on at least one surface of said flexiblesupport,wherein said pressure sensitive adhesive is leaves no residueafter laundering or is repulpable when tested according to TAPPI testUM-213.